Dual solenoid operated bidirectional control means



H. TYZACK 3,024,375 DUAL SOLENOID OPERATED BIDIRECTIONAL CONTROL MEANS March 6, 1962 Filed March 10, 1958 Havo Zd yfiENToR' 16a 142" 17a 64 5a 80.

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ite State 3,024,32 Patented Mar. 6, 1962 3,024,375 DUAL SOLENSH) UPERATED BIETEREQTFJNAL CONTROL MEANS Harold Tyzack, Schiiler Park, Ill., assignor to Motorola, Inc, Chicago, 111., a corporation of liiinois Filed Mar. 10, 1958, Bar. No. 72il,@7 5 Claims. (Cl. 31-24) This invention relates to rotatable control means and more particularly to electrically operated remote control means movable stepwise to diiferent operative positions by means of a rotatable control shaft.

Remotely operated rotatable control means find application in a number of electronic devices such as radio and television receivers in connection with the control and tuning of such devices by means of switches, potentiometers, variable capacitors and the like. In the past, adjustment of such components has often been accomplished by a rotatable shaft driven by an electric motor responsive to remote control means. The provision of such a motor and of the associated moving parts has added undesirably to the complexity, size and expense of electronic apparatus. In addition, a fairly high current level power source must be provided for driving the motor or a relay must be incorporated into the circuit. Since it is desirable that the aforementioned control shaft be capable of rotating in either direction, means must be provided for reversing the driving direction of the controlling motor as by reversing the direction of the current supplied to the motor, or a reversing gear arrangement must be incorporated into the apparatus.

It has also been proposed to operate a rotatable control shaft through the action of a solenoid plunger by imparting rotary motion to such plunger as it is actuated and deactuated. However, such arrangements have provided for the rotation of the control shaft in one direction only, whereas bidirectional control is desirable in a number of applications such as volume control in the audio portion of a radio or television receiver.

It is an object of this invention to provide inexpensive, simple and compact electrical apparatus for remotely operating rotatable control means.

It is a further object of the invention to provide inexpensive apparatus for controlling in a stepwise manner the rotation of a control shaft in either direction particularly in connection with the remote tuning of electronic apparatus.

It is still another object of the invention to provide a compact device operated by a low power electric source for driving a control shaft in either direction without back driving the shaft.

A feature of the invention is the provision of a pair of solenoid operated plungers each of which is adapted to rotate on reciprocal motion caused by the actuation and deactuation of the solenoid and each of which carries a rotating driving member which moves into operative connection with a control shaft positioned between the plungers and turns it a predetermined amount on actuation of the particular solenoid. The plungers are adapted to impart rotation to the control shaft in different directions. The solenoids have high impedance windings and draw less current than a shaft-turning motor so that they can be actuated by a relatively low power source such as a vacuum tube.

Another feature of the invention is the provision of a rotating drive member carried on each of the aforementioned solenoid plungers and connected by a onewayclutching arrangement to a plate fixed to the plunger so that the driving member will rotate with the plunger shaft during the plungers actuating stroke to rotate the control shaft but which remains fixed when the plunger rot-ates in the opposite direction on its deactuated return strok and so does not back drive the control shaft.

A further feature of the invention is the provision of a pair or" guide members each having slanted camming surfaces thereon cooperating with a radial projection on each of the aforementioned solenoid plungers to impart rotary motion to each plunger as it moves reciprocally on solenoid actuation and deactuation. The camming surface of each guide member is so arranged that each plunger will rotate in a. different direction on its actuated stroke, and the direction of rotation of the control shaft is determined by selective actuation of the solenoids.

in the accompanying drawings:

FIG. 1 is a view in front elevation and partly in section of a particular embodiment of the present invention showing the arrangement of the solenoids and the control shaft;

FIG. 2 is a view in section taken on the line 2-2 of FIG. 1;

FIG. 3 is a broken-away view in elevation showing one of the solenoid plungers in position for rotating a control shaft;

FIG. 4 is a view in section taken on the line 4-4 of FIG. 1;

FIG. 5 is a view in section taken on the line 55 of FIG. 2; and

FIG. 6 is a view in section taken on the line 6-6 of FIG. 2.

In accordance with the present invention there is provided on opposite sides of a rotatable control shaft a pair of solenoids which have plunger members extending parallel to the control shaft. Each of the solenoid plungers carries a radial projection which moves into contact with a slanting camming surface of a guide member when the plunger moves linearly on actuation of the solenoid. This imparts a twisting or rotary motion to the solenoid plunger in addition to its linear motion. The guide members associated with each of the solenoid plungers have their camming surfaces cut along such a direction as to rotate the plungers in opposite directions on their actuated stroke. Each plunger carries a driving wheel which is moved into engagement with a driven wheel connected to the control shaft upon actuation of the solenoid. The rotary motion of the plunger is imparted to the control shaft through the engagement of the wheels thus turning it through a predetermined angle. When the solenoid is deactuated, the plunger is returned to its normal position by the action of a spring and is twisted in the opposite direction by the bearing of its projection against the camming surfaces. However, since the driving wheel is connected to the plunger through a one-way clutch, it remains stationary on the return stroke and does not back drive the control shaft.

The rotation of the control shaft in the opposite direction is accomplished by actuation of the other solenoid the plunger structure of which is adapted to rotate in the opposite direction from the first. In this way, bidirectional rotation of the control shaft can be accomplished simply by means of a compact and inexpensive device.

The accompanying drawings show a control device generally indicated at it which includes the mounting bracket 11 which supports a variable control device such as the potentiometer 1?; which is connected to the control shaft 13. The control shaft 13 is provided with a pin 14 extending from the flattened surfaces 16a and 16b of an enlarged portion 16. As particularly shown in FIG. 4, flattened portions 16a and 16b fit against corresponding flats 17a and 17b of collar 17 so that shaft 13 is turned by rotation of the collar while the latter may slide longitudinally along the enlarged portion 16. Annular rubber wheel 18 fits tightly around the collar 17 being secured to the shoulder 19 thereof. The collar 17 is held against projecting pin 14 by the spring 21 working against sleeve 2%) which rests on the collar and is mounted freely around the control shaft. Control device 10 is mounted in a television receiver or the like with shaft 13 accessible for manual adjustment when desired.

Solenoids 22 and 23 are mounted on the bracket 11 on either side of the control shaft 13 by screws 24. The solenoids 22 and 23 are each identical in construction except for differences in the guide members associated therewith and include a high impedance magnetic coil 2% (FIG. 2) wound on a spool 27 held within a housing 28. The coil 26 of solenoid 22 is connected to a current source indicated at 29 for remotely controlled actuation by a switch 31 which is conveniently a pushbutton while the corresponding coil of solenoid 23 is connected to current source 32 (or to the same current source) by a similar switch 33. Since the solenoid coils 26 are of high impedance (as compared with an electric motor) they draw a relatively small current and can be actuated by a relatively low power source such as a vacuum tube without the use of a relay. Each of the solenoids further provided with a plunger member 34 shown in its unactuated position in FIG. 2 which moves axially within the spool 27 and has its end portion 34a drawn into the seat member 36 when the coil 26 is actuated.

The plunger 34 of solenoid 23 has a collar 37 riding freely thereon adjacent to the end remote from the seat 36. An annular driving member or wheel 38 of rubber or similar resilient material fits around the collar 37 being glued or otherwise fixed to the shoulder 37a and is provided with beveled surface 38a adapted to engage the similarly sloping beveled surface 18a of the wheel 18 around the control shaft. A plate 4i, held to the end of plunge 34 by the screw 42, is in one-way driving rela tion with the collar 37 through metal balls 43 held within suitable openings in rubber disc 44. The surface of plate 41 is provided with camming pockets 46 with one for each ball 43. As shown particularly in FIG. 1, each camming pocket 46 has a wedging surface 47 which serves to lock the balls 43 against collar 37 when plate 41 and plunger 34 rotate in one direction to rotate collar 37 and the wheel 38 while permitting the plunger 34 to rotate freely within the collar 37 when it twists in the opposite direction.

The plunger 34 of solenoid 22 is provided with a 1 collar 48 which carries a rubber driving member or wheel 49. The same type of clutching arrangement is employed as that described in connection with solenoid 23 except that the driving direction is reversed.

Each of the solenoid plungers 34 carries a radial projection 51. The projection 51 of the plunger of solenoid 22 is arranged to fit within slanting slots 52 and 53 of the guide member 54 which includes two semicylindrical half portions 55 and as (see FIG. 4) depending from the bottom of coil housing 28. Spring '7 extends around the guide portion 54. Similarly guide membe 58 (which is associated with solenoid 23) including scmicylindrical half portions 59 and 61 is provided with slanting slots 62 and 63 engaging the projection 51 on the plunger 34. As shown in FIG. 1 the corresponding slots of the guide portion 54 slope oppositely from those of guide portion 58. A spring 64 similar to spring 57 fits around the guide member 58.

In operating the device to rotate control shaft 13 in a counterclockwise direction as viewed in PEG. 4, switch 31 is closed thus energizing the coil 26 of the solenoid 22 and causing the plunger 34 to move linearly toward the end 22a of the solenoid (H8. 1). The linear movement of plunger 34 causes the projection 51 to bear against the sloping edges defining slots 52 and 53 and imparts a twisting clockwise (as viewed in FiG. 4) motion to plunger 34 and to plate 41 secured to its one end. The rotation of plate 41 in this direction wedges balls 43 against collar 48 thus rotating it and wheel 49. As beveled surface 49a is carried into contact with beveled surface 18a by linear movement of plunger 34, it slidcs collar 17 along shaft 13 toward potentiometer 12 at the same time rotating driven wheel 18, and control shaft 13 in a counterclockwise direction from the viewpoint of FIG. 4. The resistance provided by spring 21 holds surfaces 49a and 18a in driving engagement during the actuation stroke of plunger 34 and the friction between the rubber surface prevents relative slippage. The amount of rotation of plunger 34 and therefor of shaft 13 is predetermined by the inclination of slots 52 and 53 with respect to the plunger axis.

Opening of the switch 31 deenergizes coil 26 of the solenoid 22 and its plunger is restored to the unactuated position shown in FIG. 1 by the action of the spring 57 working against the top of collar 4-8. On the return stroke, the plunger 34 is twisted in the opposite direction by movement of projection 51 in slots 52 and 53. Spring 21 slides collar 17 toward pin 14 so that surfaces 18a and 490 are in contact during a part of the return stroke of plunger 34. Because of the one-way clutching action provided by balls 43 and wedging surfaces 47, the plate 41 of solenoid 22 slips with respect to the collar 48 on the return stroke. The wheel 49 thus remains stationary and thus does not impart any back driving to wheel 18 in the course of such return stroke.

When it is desired to rotate the control shaft 13 in a clockwise direction as viewed in FIG. 4, switch 33 is closed and analogous action takes place in solenoid 23 except that its plunger 34 rotates in opposite direction from the plunger of solenoid 22 because of the configuration of the slots 62 and 63 of guide member 58. Back driving of wheel 18 by wheel 37 on the return stroke of the plunger is prevented because of the one-way clutching arrangement associated with solenoid 23 which, as previously explained, permits slippage in the opposite direction with respect to the corresponding clutch of solcnoid 22.

In some instances, as where the potentiometer 12 is used for volume control in the audio portion of a tele- VlSlOIl receiver, it may be desirable to advance the control shaft 13 in the desired direction by several incrc ments with a single actuation of the remote control switches 31 and 33. This can be accomplished by providing a pulsating current from the sources 29 and 32. Switches 31 or 33 may be held in the closed position until the necessary number of pulses have been delivered to successively actuate and deactuate the corresponding solenoid and its associated plunger to rotate the control shaft to the position desired. Although separate current sources are shown for the sake of clarity, it will be undcrstood, of course, that a common current source may be used for both solenoids 22 and 23 and controlled by separate switches or by other suitable control means.

Although the embodiment particularly illustrated shows projections 51 as extending radially from both sides of the plunger, it will be understood that a projection extending from only one side may also be used. in such cases only a single slanted camming slot need be provided for each guide member.

The present invention thus provides a simple, compact and relatively inexpensive device for bidirectional rotation of control shafts. By providing a pair of solenoids whose plungers twist in opposite directions when actuated, rotation in either direction can be obtained. The use of solenoids to supply the rotary drive permits use of a. lower power current source than could ordinarily be employed in running an electric motor. The one-way clutching mechanism described permits the rotary motion of the plungers to be transmitted to the shaft during only one stroke of their reciprocal movement thus avoiding undesired back driving during the other stroke.

1 claim:

1. Electrical control apparatus for stepwise rotation of a shaft, said apparatus including in combination, a control shaft, a pair of solenoids each having a plunger reciprocally movable along its axis between actuated and unactuated positions, means for actuating said solenoids, said plungers positioned on opposite sides of said shaft and extending parallel thereto, a collar extending around said shaft and connected thereto to slide along said shaft and rotate therewith, a driven wheel of resilient material fixedly mounted on'said collar, a spring urging said collar to a rest position, a radial projection extending from each of said plungers, guide means including slanting cam means for engaging said projection of its corresponding plunger during reciprocal movement of said plunger to impart a predetermined rotary motion thereto, the alignment of the cam means formed in the guide means being such that clockwise rotary motion is imparted to one of said plungers as it moves to its actuated position and counterclockwise rotary motion is imparted to the other of said plungers as it moves to its actuated position, a driving wheel of resilient material mounted on each of said plungers and adapted for separate movement into driving relation with said driven wheel on said collar during axial movement of said plunger to its actuated position, with actuation of one of said plungers effecting counterclockwise rotation of said shaft and at:- tuation of the other of said plungers effecting clockwise rotation of said shaft, and one-way clutch means associated with each of said driving wheels to prevent rotary movement of said driving wheel as its corresponding plunger moves from its actuated to its unactuated position.

2. The apparatus of claim 1 wherein said one-way clutch means includes a plate fixedly mounted on said plunger for rotation therewith and axially spaced from said driving wheel, a ball in contact with said driving wheel and a face of said plate, and camming means formed in said face adapted to wedge said ball into driving relation between said plate and said driving wheel on rotation of said plunger in one direction and to permit relative rotation of said plate with respect to said driving wheel on rotation of said plunger in the opposite direction.

3. Electrical control apparatus including in combination, a frame having first and second opposite ends, a control shaft rotatably mounted in said frame and extending longitudinally toward said ends thereof, a driven wheel supported on said shaft, means coupling said driven wheel to said shaft for rotating said shaft and permitting movement of said driven wheel along said shaft toward said first end of said frame, a stop defining a rest position for said driven wheel, a spring urging said driven wheel toward said second end of said frame against said stop, a pair of solenoids supported by said frame and each including a rotatable plunger movable reciprocally in the direction of said shaft, said plungers being positioned on opposite sides of said shaft and parallel thereto, earn means associated with each of said plungers for rotating said plungers in opposite directions during such reciprocal movement, a pair of driving wheels associated respectively with said plungers, said driving wheels being positioned between said driven wheel and said second end of said frame and movable by the respective plunger upon actuation of the corresponding solenoid to engage and move said driven wheel along said shaft toward said first end of said frame, means for actuating said solenoids independently, and one-way clutch means coupling said driving wheels to said plungers for rotating said driving wheels during the aforesaid movement thereof toward said first end of said frame, thereby rotating said shaft, said clutch means preventing rotation of said driving wheels during return movement thereof toward said first end of said frame so that said shaft is not driven backwards.

4. Electrical control apparatus including in combination, a frame having first and second opposite ends, a control shaft rotatably mounted in said frame and extending longitudinally toward said ends thereof, a toothless driven wheel supported on said shaft, means coupling said driven wheel to said shaft for rotating said shaft and permitting movement of said driven wheel along said shaft toward said first end of said frame, a stop defining a rest position for said driven wheel, a spring urging said driven wheel toward said second end of said frame against said stop, a pair of solenoids supported by said frame and each including a rotatable plunger movable reciprocally in the direction of said shaft, said plungers being positioned on opposite sides of said shaft and parallel thereto, cam means associated with each of said plungers for rotating said plungers in opposite directions during such reciprocal movement, said cam means including members having slanting slots and a projection extending from each plunger into a corresponding one of the slots, a toothless driving wheel positioned between said driven wheel and said second end of said frame and movable by said plungers upon actuation of said solenoids to engage and move said driven wheel along said shaft toward said first end of said frame, and one-way clutch means coupling said driving wheels to said plungers for rotating said driving wheels during the aforesaid movement thereof toward said first end of said frame, said driving wheels having a substantial coefficient of friction with respect to said driven wheel so that the engaged wheels are effectively coupled together and said shaft is rotated thereby, said clutch means preventing rotation of said driving wheels during return movement thereof toward said first end of said frame so that said shaft is not driven backwards.

5. Electrical control apparatus including in combination, a frame, an elongated control shaft rotatably supported by said frame, a driven wheel supported on said shaft, means coupling said driven wheel to said shaft for rotating said shaft and permitting movement of said driven wheel along said shaft between first and second positions, means urging said driven wheel to said first position thereof, a pair of solenoids supported by said frame and each including a rotatable plunger movable reciprocally in the direction of said shaft, means associated with each of said plungers for rotating said plungers in opposite directions during such reciprocal movement, a pair of driving wheels associated respectively with said plungers, said driving wheels each having a rest position on the same side of said driven wheel and each being movable by the respective plunger upon actuation of the corresponding solenoid to engage and move said driven wheel along said shaft to said second position thereof, said driving wheels being completely disengaged from said driven wheel in said rest position thereof, means for actuating said solenoids independently of each other, and one-way clutch means individually coupling said driving wheels to said plungers upon actuation of the associated solenoid so as to rotate said shaft in a forward direction upon engagement of a driving wheel with said driven wheel, said clutch means being adapted to prevent rotation of said driving wheels during return movement of said driven wheel from said second position to said first position so that said shaft is not driven backwards.

References Cited in the file of this patent UNITED STATES PATENTS 1,367,283 Simon Feb. 1, 1951 2,752,513 Boyd June 26, 1956 2,763,793 Krasney Sept. 18, 1956 2,887,889 Parisoe et al May 26, 1959 FOREIGN PATENTS 649,109 France Oct. 21, 1928 

